1. Field of the Invention
The present invention relates to manufacturing method of a color filter substrate, and more particularly, facing a thin film transistor substrate in a liquid crystal display.
2. Description of the Related Art
In general, a liquid crystal display includes two substrates that have electrodes and face each other, a liquid crystal material therebetween, and a sealant sealing the liquid crystal material.
One of the two substrates has a black matrix and red, green and blue color filter, and the other has a plurality of thin film transistors (TFTs) and pixel electrodes.
FIG.1 is a cross-sectional view of two substrates in a liquid crystal display (LCD).
As shown in FIG.1, a black matrix 2, partially covered by color filters 3 in the display region P and another black matrix 21 are formed on a color filter substrate 1. An indium tin oxide (ITO) layer 4 is overlaid on the color filters 3 and the black matrices 2 and 21.
A thin film transistor substrate 5, which is facing opposite the foregoing substrate 1, has a passivation layer 6 on the facing side.
A sealant 8 joins the two opposing substrates 1 and 5. A liquid crystal material 7 is then injected into the space between the two facing substrates 1 and 5.
Referring to FIG. 1, a conventional manufacturing method of an LCD will be described, emphasizing a manufacturing method of a color filter substrate.
A layer of chromium is sputtered on a transparent substrates 1 to a thickness between 500 to 2000 .ANG. to create black matrices 2 and 21, which prevent TFTs from being degraded from exposure to light.
A photoresist, with optimal spectral properties, is coated thereover, and developed to form a red color filter 3.
Blue and green color filters 3 are formed in the same manner as the red color filter 3.
An ITO layer 4 is formed on the substrate 1 having color filters 3, thus completing the color filter substrate 1.
Finally, a liquid crystal display is completed by applying a sealant 8 on the edge of one of the two substrates 1 and 5, joining the two facing substrates 1 and 5, and injecting a liquid crystal material 7 between the two opposing substrates 1 and 5.
However, in the application of conventional manufacturing methods of LCDs, the adhesive strength between the color filters, the black matrices, and the ITO layer is compromised by either residual pigment remaining on the surface of the black matrix, and/or any moisture or gas in the color filters remaining from the evaporation when forming the ITO layer.